I don't understand your analogy, because to me Libertarians are idealists. They're a lot like socialists, except with a conservative rather than liberal worldview. I can't figure out how to see them as "pessimist" in an intuitive enough sense to be able to properly map that feeling onto your second statement and solve for X.

I've also heard: "Libertarianism is Anarchism for rich people", which isn't quite accurate but has a very big grain of truth to it.

I disagree that libertarians are pessimists. We're the ultimate optimists. We believe that the people, left to their own devices and with no government meddling, will do the right thing. I've read economic textbooks, and remain optimistic about individuals' ability to determine their own actions without the need for State interference.

So, your analogy is based on a flawed premise. Or perhaps the answer is: